请问这个程序的错误是什么意思

刚开始学OPENGL第一章,就被第一个程序给郁闷了
编译后显示的错误是:
-3.obj : error LNK2001: unresolved external symbol ___glutInitWithExit@12
1-3.obj : error LNK2001: unresolved external symbol ___glutCreateWindowWithExit@8
Debug/1-3.exe : fatal error LNK1120: 2 unresolved externals
Error executing link.exe.1-3.exe - 3 error(s), 0 warning(s)
我的源代码是:
#include<windows.h.>
#include<GL/gl.h>
#include<GL/glu.h>
#include"GL/glext.h"
#include<stdio.h>
#include<stdlib.h>
#include<GL/glut.h>
static GLfloat spin=0.0;void init(void)
{  
   glClearColor(0.0,0.0,0.0,0.0);
   glShadeModel(GL_FLAT);
}void display(void)
{
   glClear(GL_COLOR_BUFFER_BIT);
   glPushMatrix();
   glRotatef(spin,0.0,0.0,1.0);
   glColor3f(1.0,1.0,1.0);
   glRectf(-25.0,-25.0,25.0,25.0);
   glPopMatrix();
   glutSwapBuffers();
}void spindisplay(void)
{
   spin=spin+2.0;
   if(spin>360.0)
       spin=spin-360.0;
   glutPostRedisplay();
}void reshape(int w,int h)
{
glViewport(0,0,(GLsizei) w,(GLsizei) h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-50.0,50.0,-50.0,-50.0,-1.0,1.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}void mouse(int button,int state,int x,int y)
{
switch(button) {
   case GLUT_LEFT_BUTTON:
      if (state==GLUT_DOWN)
     glutIdleFunc(spindisplay);
  break;
   case GLUT_MIDDLE_BUTTON:
  if (state==GLUT_DOWN)
 glutIdleFunc(NULL);
  break;
   default:
      break;
}
}
//请求使用双缓存模式
//注册响应鼠标事件的回调函数
//
int main(int argc,char** argv)
{
  glutInit(&argc,argv);
  glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB);
  glutInitWindowSize(250,250);
  glutInitWindowPosition(100,100);
  glutCreateWindow(argv[0]);
  init();
  glutDisplayFunc(display);
  glutReshapeFunc(reshape);
  glutMouseFunc(mouse);
  glutMainLoop();
  return 0;
}